It is common practice to spray and dust plants to kill insects, bugs, etc., and numerous types of powder and liquid dispersing devices are in common use. A device for spraying liquid in air wholly unsuited for powder has cylinder and piston arrangement in combination with a reservoir positioned on one side of the pump which pumps a stream of air which draws liquid to be dispersed into the pump cylinder thereof and disperses liquid and air mixture. This type of apparatus has many disadvantages. Also the inventors of U.S. Pat. to McRoskey, et al. No. 3,904,087, issued Sept. 9, 1976, entitled Compartmented Powder Dispersing Device, have devised the structure shown therein for dispersing powder.